The first fossil fungus gardens of Isoptera: oldest evidence of symbiotic termite fungiculture (Miocene, Chad basin)

Abstract

Higher termites of the subfamily Macrotermitinae (fungus-growing termites) are known to build fungus gardens where a symbiotic fungus (Termitomyces sp.) is cultivated. The fungus grows on a substrate called fungus comb, a structure built with the termites' own faeces. Here we present the first fossil fungus combs ever found in the world. They were extracted from 7-million-year-old continental sandstone (Chad basin). Fossilized fungus combs have an ovoid morphology with a more or less flattened concave base and a characteristic general alveolar aspect. Under lens, they display a typical millimetre-scale pelletal structure. The latter, as well as the general shape and alveolar aspect, are similar to the morphology of fungus combs from extant fungus-growing termites.

Termites (Isoptera): Their Phylogeny, Classification, and Rise to Ecological Dominance

“…Were Termitidae abundant during the Eocene they should have been preserved in Baltic amber (Lutetian: ca. 45 Ma), since this deposit has yielded thus far most other living termite families Engel, 2008), as well as species belonging to a diversity of other tropical insect groups (Duringer et al, 2006). Throughout the Cretaceous and early Tertiary, including the mid-Eocene, termites represented less than 1% of all insect specimens in all fossil deposits ( fig.…”

Cosmogenic nuclide dating of Sahelanthropus tchadensis and Australopithecus bahrelghazali : Mio-Pliocene hominids from Chad

“…Atmospheric 10 Be, a cosmogenic nuclide, was used to quasicontinuously date these sedimentary units. The authigenic 10 Be/ 9 Be dating of a pelite relic within the sedimentary level containing Abel yields an age of 3.58 ؎ 0.27 Ma that points to the contemporaneity of Australopithecus bahrelghazali (Abel) with Australopithecus afarensis (Lucy). The 28 10 Be/ 9 Be ages obtained within the anthracotheriid unit containing Toumaï bracket, by absolute dating, the age of Sahelanthropus tchadensis to lie between 6.8 and 7.2 Ma.…”

“…The authigenic 10 Be/ 9 Be dating of a pelite relic within the sedimentary level containing Abel yields an age of 3.58 ؎ 0.27 Ma that points to the contemporaneity of Australopithecus bahrelghazali (Abel) with Australopithecus afarensis (Lucy). The 28 10 Be/ 9 Be ages obtained within the anthracotheriid unit containing Toumaï bracket, by absolute dating, the age of Sahelanthropus tchadensis to lie between 6.8 and 7.2 Ma. This chronological constraint is an important cornerstone both for establishing the earliest stages of hominid evolution and for new calibrations of the molecular clock.…”

“…beryllium-10 ͉ absolute dating ͉ hominid site ͉ Abel ͉ Toumaï W e determined authigenic 10 Be/ 9 Be ages at two hominid localities in the Chad Basin (Djurab Desert of northern Chad). The focus of this study was the Toros-Menalla (TM) fossiliferous area, where Sahelanthropus tchadensis (Toumaï) was unearthed.…”

Diversity, population genetics, and evolution of macrofungi associated with animals

“…Duringer et al (2006) reported the first fossil fungal combs extracted from a 7-million-year-old continental sandstone, the oldest symbiotic termite fungiculture known at that time. More ancient fossil evidences were subsequently reported (Duringer et al 2007), further demonstrating the long-term association between symbiotic fungi and termites.…”